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The purpose of this chapter is to review the concept of circular economy in the context of logistics and supply chain, which it is crucial in dealing with climate change. To strengthen the circular supply chain, this chapter proposed the Quadruple Helix logistics model (QHLM). The model emphasized corporate spirituality values that instill responsibility for environmental, social, and economic sustainability in four key components: the government, university, logistics companies/departments, and community, all of which are thought to be critical for the success of circular economy implementation, resulting in sustainable development. Finally, this chapter discusses the future prospects of logistics within the circular economy concept, presenting a win-win situation between environmental conservation, societal well-being, and business sustainability.

This paper describes the reaction mechanism to deposit pyrolytic carbon within porous body of char derived from oil palm empty fruit bunch (EFB) via an integrated pyrolysis-tar decomposition process, which employs chemical vapor infiltration method. This process was developed to produce a value-added EFB-derived char and to make EFB able to be utilized as a supplementary solid biofuel. The product, namely carbon-deposited char, was characterized in comparison with metallurgical coke breeze used in iron-steel industry.

This project investigates the influence of dopants use via hot-isostatic pressing (HIP) sintering technique on thermoelectric properties. A total of 8 samples weighing 3 g each at different compositions (Zn4-xMxSb3) (M = Cu, Al) (x = 0, 0.3, 0.6 at.%) were prepared via powder metallurgy technique and followed by HIP sintering process. The relative density of all the samples recorded 85-95% which is comparable to the published data. From the XRD results, a near single phase of Zn4Sb3 was obtained. The SEM images revealed a minor of porous surface exist and showed metallurgical bonding formed in the prepared samples. From thermoelectric properties characterization, Cu showed as an effective element to lower the electrical resistivity as compared to Al when Sample 6 (Zn3.4Cu0.6Sb3) recorded 16.18×10−5 Ωm and Sample 8 (Zn3.4Cu0.6Sb3) was 27.09×10−5 Ωm. The results showed that HIP sintering technique at lower temperature compare to others studies offers potential processing route to produce a good thermoelectric material associated with the doping element.

Nowadays, the used of NiTi shape memory alloys in biomedical field is growing exponentially linear with technological advancement. With all great benefits from NiTi, however, they also come with certain level of toxicity that can harm human’s health sourcing from the Ni itself. Many techniques have been developed to contain this Ni from leaching out from the NiTi shape memory alloys. Among the techniques, thermal oxidation via annealing treatment is chosen where TiO2 is expected to form on the surface of the NiTi shape memory alloys and may act as a barrier to prevent the Ni from leaching out. Therefore, this research investigates the effect of annealing treatment to produce the optimum thickness of the oxide layer with good martensitic transformation behavior. In this case, NiTi was annealed from 400 °C to 700 °C for duration of 10 to 300 minutes in a furnace. The thickness of oxide layer was characterized using SEM and the transformation behavior was analyzed using DSC equipment. Based on the results obtained from SEM and DSC, by increasing annealing temperature and time, the thickness of the oxide layer increases and more even, however, it reduces the enthalpy change. Therefore, samples annealed at 600 °C for 50 to 150 minutes is an optimum parameter to produce the appropriate thickness and uniformity of the oxide layer (∼22 - 26 µm) with reasonable Ms and enthalpy changes (ΔHA→M = 7.50 to 9.62).

Silica in the nanoscale has interesting properties compared to its bulk counterpart that leads to a different range of applications. This is due to its low toxicity, high physical and chemical stability, large surface area to volume ratio and direct surface chemistry that allows to be combined or functionalized with a variety of functional species or molecules. Most researches used metal alkoxides or agricultural materials for the source of silica but very few researches attempted at preparing nano-silica powder from silica sand via the chemical method. In this research, the nano-silica powder is prepared via sol-precipitation method and its subsequent characterization. The materials used for this project were silica sand, sodium hydroxide, hydrochloric acid and distilled water. Surface morphology using Field Emission Scanning Electron Microscope (FESEM) of the silica sand was found to be irregular in terms of its size and shape. The average particle size of the silica sand determined by FESEM was found to be around 230 µm. The nano-silica has quartz SiO2 structures as demonstrated from XRD analysis. The synthesized nano-silica particle have a huge reduction in terms of size between 58 nm to 290 nm using FESEM. It was also found that the nano-silica particles were very agglomerated and had a spherical or globular particle shape. Hence, the silica sand can be an alternative precursor for synthesis of nano-silica particle by the sol-precipitation method instead of using other chemical precursor.

Zinc anode is electrodeposited from a 2-M zinc chloride electrolytic bath with varying ammonium chloride supporting electrolyte concentrations (0-5 M) and plating current density (0.1 – 0.6 A cm-2). The total charge quantity supplied during electrodeposition is fixed at 150 mAh. Alkaline zinc-air cell is fabricated using the electrodeposited zinc anode and characterized according to its discharge capacity at constant load current of 20 mA. The effect of various qualities of zinc electrodeposits on the cell discharge performance is discussed. It is found that zinc electrodeposits prepared from electrolytic bath of 5-M ammonium chloride and 0.5 A cm-2 plating current density produced zinc-air cell with the highest output energy i.e. 24 mWh. We observe that the influence of plating current density is more prominent than the plating bath formulation on the zinc anode performance in the cell.

This work explores the use of metal-air electrochemical system to evaluate porous electrode properties i.e. specific surface area and pore volume density. Porous zinc electrodes are prepared from an acidic, chloride electrolytic bath of varying supporting electrolyte (NH4Cl) formulation to produce electrodeposits of distinctive properties. Nitrogen physisorption at 77 K is utilized to evaluate the specific surface area and pore volume density of the electrodes. The zinc electrodeposits prepared from all electrolytic bath formulations are then assembled into zinc-air cells as the anodic electrode and characterized according to their limiting current density and discharge capacity. It is found that the variation in limiting current density matches that of BET surface area and the trend for discharge capacity follows that of pore volume density.

Ceramic membranes became one of the most important ceramic products because of their numerous benefits to many applications especially in gas separation processes. The attractive features offered by this technology include high energy efficiency, simplicity design and construction of membrane modules and environmental compatibility. The aim of this project is to get the optimum calcination temperature thus will give the optimize pore size for separation gas without cracking or pinholes the membranes. Therefore, the silica ceramic membrane was fabricated via sol-gel dip-coating method and the effect of calcination temperature on the membrane pore size was investigated. The ceramic support was dipped in the mixture solution of tetraethyl orthosilicate (TEOS), distilled water, ethyl alcohol and nitric acid with the desired molar ratio followed up by the calcination process at 400 °C, 500 °C and 600 °C. For X-ray diffraction (XRD) results, the fabricated silica ceramic membrane shows the existence of silicate hydrate when calcined at 400 °C, 500 °C and 600 °C. The XRD analysis showed the highest peak intensity at 22.5° which proved the presence of silica. From the field emission electron microscopy (FESEM) images, the pore size of the ceramic support was around 0.5 to 0.6 μm. After the silica ceramic membranes were fabricated, the pore size no longer visible under the FESEM proves that the pore size of the membranes was reduced. Fourier transform infrared spectroscopy (FTIR) showed adsorption spectra of the fabricated membranes with different calcination temperature. The broad band in the region around 1060 to 1090 cm-1 correspond to the O-Si-O bond of mesoporous silica altogether confirming the existence of silica. Based on the result analysis, the suitable calcination temperature at 500 °C with less crack and more consolidated surface membrane.

Ceramic membranes are an inorganic membrane that received great attention as it overcome the limitation of polymeric membrane. The silica ceramic membrane can be used in gas separation as it able to work at elevated temperature and in chemically aggressive environment. This work is conducted to study the influence of the molar ratio of water (R) on the fabrication of silica ceramic membrane by sol-gel dip-coating method. Commercial support was dipped into the solutions consist of the mixture of tetraethylorthosilicate (TEOS), distilled water and ethanol with the addition of a small amount of acid as a catalyst. The molar ratio of TEOS toethanol was fixed at 1 to 3.8 (TEOS:ethanol, 1:3.8). However, the molar ratio of water are varied at 2, 3, 4 and 4.7. FESEM (Field Emission Scanning Electron Microscope), XRD (X-ray Diffraction) and FTIR (Fourier Transform Infrared Spectroscopy) are utilized to determine the structural and chemical properties of silica ceramics that are fabricated with different R. FESEM images implied that the silica has been deposited on the surface of silica membrane and penetrate into the pore walls. XRD analysis of the fabricated silica ceramic membranes illustrated the existence of silicate hydrate. The fabricated silica ceramic membrane with silica sol molar ratio 1:3:3.8 gave the lowest intensity of XRD peak. FTIR analysis, it was observed that the presence of Si-O-Si functional group is in the range 1060 to 1080 cm-1.

The purpose of this study is to identify theZn2+ions concentrationat Sn-Zn coating which could be produced in the absence of a complexing agent. The electrolytic bath comprised of SnCl2 and ZnCl2. The ionic mole ratio Zn2+/Sn2+ of the electrolytic bath studied were 1:2, 1:1, 2:1, 4:1 and 10:1. Pure Zn and Sn electrodeposits were also prepared. The deposition process was performed at constant current of 5 mA and deposition time of 120 min. The electrodeposits were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that in the absence of complexing agent, even an electrolytic bath with Zn2+/Sn2+ ionic ratio of ten folds could not produce Zn-rich of Sn-Zn electrodeposits. Further, a unique method has been introduced to characterize the electrodeposits i.e. using the metal-air electrochemical cell. In this method, the electrodeposits were coupled with an air electrode in an alkaline electrolyte (6 M KOH) and discharged at 1 mA. Specific metallic element content will produce a distinct discharge profile thus enables it to be used in characterizing alloys or composites.

Zinc antimonite, Zn4Sb3 is a promising thermoelectric material because of its high thermoelectric performance and abundance of Zn and Sb in nature. Thus, in this study, samples of Zn-Sb alloy were prepared using electrodeposition method because of its simple experimental set-up, which also carried out in the room temperature. From the XRD results, all samples deposited exhibit Zn-Sb alloy compositions. The best results were S1 and S3 as they had dominant peaks that showed the crystal lattice of Zn4Sb3. From the SEM images, the surface morphology of Zn-Sb alloy deposited samples showed were all-irregular, course and rough structures. While, the atoms arrangement of the deposited samples were all flowery-like. Based on physical properties characterization, the best samples; S1 (0.1M ZnCl2-0.1M SbCl3, 100mA, 120min) and S3 (0.1M ZnCl2-0.1M SbCl3, 50mA, 120min), were selected and investigated their thermoelectric performances; electrical conductivity and Seebeck coefficient, to determine their power factor, PF. Heat capacity of the samples was also examined to relate it with thermal conductivity of Zn-Sb deposited samples. For thermoelectric performance, S1 obtained power factor of 1.37x10-7V/K. Ω.cm at 102°C with the Seebeck coefficient of 181μV/K. While as for S3, the power factor was 1.58x10-7V/K. Ω.cm with Seebeck coefficient of 113μV/K at 101°C. From DSC analysis, it showed that S3 obtained higher Cp than S1. Cp for S3 was 46.8093mJ/°C while S1 was 38.3722mJ/°C.

Fabrication of silica ceramics via the sol-gel method has offered more advantages over other methods in the fabrication of ceramic membrane, such as simple operation, high purity homogeneous, well defined-structure and complex shapes of end products. This work presents the fabrication of silica ceramic membrane via sol-gel dip-coating methods by varying nitric acid amount. The nitric acid plays an important role as catalyst in fabrication reaction which involved hydrolysis and condensation process. The tubular ceramic support, used as the substrate, was dipped into the sol of Tetrethylorthosilicate (TEOS), distilled water and ethanol with the addition of nitric acid. The fabricated silica membrane was then characterized by (Field Emission Scanning Electron Microscope) FESEM and (Fourier transform infrared spectroscopy) FTIR to determine structural and chemical properties at different amount of acids. From the XRD analysis, the fabricated silica ceramic membrane showed the existence of silicate hydrate in the final product. FESEM images indicated that the silica ceramic membrane has been deposited on the tubular ceramic support as a substrate and penetrate into the pore walls. The intensity peak of FTIR decreased with increasing of amount of acids. Hence, the 8 ml of acid has demonstrated the appropriate amount of catalyst in fabricating good physical and chemical characteristic of silica ceramic membrane.